Posted by Polar Pilot on August 16, 2000 at 17:50:45:
In Reply to: Re: RPM's posted by Olpoky on August 15, 2000 at 22:52:09:
Exactly - but the assumption that the engine has enough power in 5th to push to those top rpm's is not necessarily the case.
This is clearer when folks are riding bikes with smaller engines. My TC250 Suzuki has a 6 speed transmission with 5th and 6th both being overdrive gears. The bike has 13,000 miles on it - but the majority of those highway mile were spent in 4th and 5th because the bike engine does not have enough power to pull the higher rpm's in the top gear. with the correct wind - it will roll along quite happily in 6th at highway speeds - give it the slightest head wind and 5th gear is required because the 30 hp engine simply cannot generate enough hummmph to drag it against a wind in the highest overdrive gear.
The 5 speed transmission on the Savage is the same - at legal riding speeds it lowers the rpm's and puts less stress on the engine - but at the highest rpm's possible - the engine may not put out enough power to hit the maximum rpms - leading to a situation where top speed wise 4th can be a faster gearing than 5th.
Quite an interesting issue really - overdrives have always been installed to conserve energy and increase engine life - but not to increase the top speed.
Our friends with 5 speed Savages may consistantly find that 4th is faster than 5th because of the energy requirements to take the bike forward at the highest possible speeds.
Keep the rubber side down
Polar Pilot